Seat suspension



Nov. 20, 1951 A s KRO-rz 2,575,496

SEAT SUSPENSION Filed Jan. 29, 1949 Patented Nov. 20, 1951 SEAT SUSPENSION Alvin S. Krotz, Akron, Ohio, assignor to The B. F.

Goodrich Company, New York, N. Y., a corporation of New York Application January 29, 1949, Serial No. 73,465

4 Claims.

This invention relates to seat suspensions for vehicles and installations where it is desirable to cushion a seat from the vibration and erratic movements of the supporting structure. The invention is especially applicable to bicycle seats Where cushioning is important because of the small amount of cushioning provided by the bicycle structure. The light weight of bicycles increases the need for adequate cushioning as bicycle structures do not have the weight necessary to absorb shocks and impacts imposed on the vehicle while traveling over rough terrain.

A seat suspension which is satisfactory for other uses may be undesirable for bicycles because the riders of bicycles use their legs to provide the propelling force and the seat suspension must be of a type to permit freedom of leg action. In addition it is necessary that lthe seat suspension provide suiiicient support as well as cushioning of the rider. It is further desirable that bicycle seat suspensions be adjustable to provide satisfactory cushioning for riders of all weights and sizes, as bicycles are ridden by both children and adults. Although bicycles have been used for several decades the seat suspensions provided have not been satisfactory because the seat suspensions have not provided the cushioning and freedom of movement required by the rider, whose comfort is almost entirely dependent upon the effectiveness of the seat suspension.

It is an object of this invention to provide an improved seat suspension which fully meets the above-mentioned requirements without necessitating the introduction of any undesirable characteristics.

Further objects are to provide cushioning of the seat in all directions through stressing of the cushioning body, to provide an improved mounting of the ycushioning body in the suspension, to provide positive limitation of the movement of the seat, to provide cooling of the cushioning body, to provide for even distribution of the stresses in the cushioning body, to provide for quiet operation of the suspension, to provide a cushioning suspension which does not require lubrication, to provide a light weight suspension, to` provide for readily adjusting the suspension to accommodate persons of different weights and to provide for simplicity and economy of construction, ease of installation and a minimum of maintenance requirements.

'Ihese and other objects will be apparent from the following description, reference being had to the drawings in which:

Fig. 1 is an elevation of a bicycle seat suspension constructed in accordance With and embodying the invention, the seat being sectioned and parts being broken away.

Fig. 2 is a section taken along line 2-2 of Fig. 1.

Fig. 3 is a view in perspective of one of the cushioning bodies of the invention.

Fig. 4 is an enlarged View of the suspension shown in Fig. 1, parts being broken away.

Fig. 5 is an enlarged section taken along line 5-5 of Fig. 4, parts being broken away.

Fig. 6 is a section taken along line 6 6 of Fig. 1.

With reference to the drawing the seat suspension of the invention is shown as applied to a bicycle seat. In Fig. 1 a conventional bicycle frame I0 is shown which is connected to the wheels, handlebars and propelling mechanism of the conventional type which are not shown. A tubular member I I of the frame projects upward from the frame and is adapted to telescopically ernbrace a post I 2. A collar I 3 is provided at the upper end of the tubular member I'I and has ears I4, I4 which may be drawn together by a bolt I5 threaded in the ears to clamp the post I2 in the desired position. As shown in Fig. 6, collar I6 is disposed about the free end of the post I 2 and has opposing anges I'I, I'I extending tangentially in parallel relationship outward from the post. Outward of the anges I l, I'I are clamping plates I8, I8 for embracing outer members I9, I9 of the cushioning structure of the invention. A bolt,2I is inserted through aligned apertures in the iianges I'I, I1 and plates I8, I8 and has a nut 22 threaded thereon for urging :the plates and anges against the members I9, I9 in clamping engagement. The members I9, I9 have a constant crosssection over a suicient length to permit movement of the members forward and rearward between the flanges I'I, II and plates I8, I8 upon release of the clamping pressure exerted by the bolt 2| and nut 22 for adjusting the position of the members relative to the post I2. The members I9, I9 may be fixed in the desired position by tightening the nut 22 on bolt ZI as described heretofore.

frame 25 of the The seat may be padded with a suitable soft material 21 such as rubber or other rubber-like material and has a covering or" wear-resisting material 28 such as polyvinyl chloride or leather.

Annular cushioning bodies 29, 2S, one of which is shown in Fig. 3, are clamped between the outer and inner members I9, I9 and 23, 23, but are otherwise unattached.YA Each body.29 has aflat face 3l andaconcave face32 providing a Gush-.-A ioning body with increased thickness at the radially outer portion. The disc portions 29, 23

abutting members I9, I9 and 23, 23 for stressing the cushioning bodies 29, 29 in shear. The apertures 35, 35 in the inner and outer members are preferably disposed adjacent the faces of the ribs 33, 33 which resist downward movement of the seat relative to the bicycle frame I9. This disposition of the apertures provides at elfective movement-resisting surfaces ot the ribs 33,

of the outer members I9, I9 of the cushioning structure are frusto-conically shaped to ccnform to the shape of the cushioningbpdies, 2 9, The abutting faces of the cushioning `bodies 2 9.,

29 are connected to the inner and outer members 33 to resist therelative movementofthe vcushioning bodies 29, 29 and the members I9, I9, and 23,

23 under the weight of the cyclist and additional vertical forces.

Additional surface for resisting relative movement is obtained when the rubber- I9, I9 and 23, 23, and relative rotation. between .A

them is prevented by suitable means. As shown in the drawing and especially in Figs. 4 and..5 the inner and outer members i9, I9 and 23, 23 have projections such as radial ribs33, 33 which proieCt-intaigdentations.Sueh es radial grecres f3.4,

34 inthe :cushioning bodies 29, 29. ld'lhelribs 33 may be made convenienl7 by shearing the members I9, I9, and l23, 23 along radiaL-lines and turningup one edge `ofthe resulting flaps Iproviding the projecting ribs with. adjacent apertures 35, asgshcrn'in Fis.,.5.j Theggrooves-S, Se in the cushioningbodies 29, 29 extend radially outpreferably evenly spaced circumferentially A of the body,A ,As shown in the drawings. the grooves 3d, gill preferably Yterminate..short of radially outer ,edges 39 :30 providing circumferentially unnterruptedanses at. the Outer periphery of the Abodyfor vreinforzaing the resulting rib portionsbetw een,the grooves and preventing foreign;

matterfrom entering the grooves. The ribs- 33, 33 are stamped inthe inner and outer members withthe grooves 34, 34 of the cushioning bodies I9 and, 23` in corresponding.ApositionstoIl mesh andprevent relative .rotation ofy the `cushioning bodies and the members at their abutting faces.

t is-,preferablethat the apertures 35, 35be1located,

at the sideof` the ribs 33, 33 which must bear the thrust-.ofthe resilient material of the cushioning bodice-,and as-showninFigs. 1 and 4 the apertures.,i,n,the outer. members I9, I9 are located; in a countercloclrwise-.direction from Ythe ribs, Yas seen from the left, and the apertures in the inner like materialof vtljrecushioning body 29 moves Vinto-the 3&Jeri'1ures-35, 35 Iof the members as shown in Fig.` 5 upon initialaxial compression of the body resulting from taking up of nut 38 on bolt 31 and upon increase of the pressure of the cushioning Ibody against the ribs resulting from torsional movement of the members of the spring whenfweightrestsronthe seat 2B. .y

The cushioning bodies V29, 2,;9 have greater axial; 1;.- thickness at,` the radially .outer edges 39, 30 which Y equalizes the stress in the vari-ous. portions ofthe body.v This construction; also permits some Sider, wise tiltingfof the seat -24 without contacter the inner and, outer rnembersZS, 23 and, I9, I9. g

The bushing ,3S disposed about the bolt1g31 prevents contact Gf-.the boltwithinnermembers-l 2e, 233 whichmightoccur during impositionof-an a excessive load `upon the spring a s se1 nbly. The` e bushing 39 furtherlserves tov carrypartpthe radial. forces exerted -fuponf the cushioning bodies-1 29, 2 9andin this way aids in equalizing'the loads- 1.AK carried by the rib portions betweenthe grooves 1 Prov-isionhas been made for the saety of the which are rigidly mounted on the bicycle frame;

members.23,r23 are located clockwise of-.the ribs.

Referring to Fig. 2 a connecting element such as alboltl and nut 38 is disposedin apertures 36, 35, inrthe disc portions 29, 29 of-A the outer members 1.9, I9, for urgingthe outer members againstthe cushioning bodies 29, 29 and the I0 and which provide ample support.

The seat ,suspension of the invention is easilyadaptablefor. carrying` riders ofv different weights. To eadjust the seatfor carrying a persongof greater weight it is only vnecessaryto loosen.;-

f; the nut 38 cnbolt'31 and in some cases the nut 22 o n the bolt V2l to spread the outer members cushioning bodies against the .inner members 23, 23, A cylindrical bushing 39 of resilient ruby ber or. otherx rubber-like material may be disposedaroundthe bolt 31 and between the'outer members 19,19. The inner members 23, 23gmay extend .inwardly and terminate in flanges forming -g an aperture ,ithrough which the bushing eX- tends end against which the bushing maybear,

In operation the weight of the cyclist is sup-,

ported for the most part at the after portion of the seatf'l yshewn at the right in Fig. l. Upward forces exerted on the bicycle tend to move the outer members l9,l9 to ward the seat 24 and `urge the inner members ,23, 2 31in a clockwisedirection about ,the axis of the bolt 31 relative tothe outer members .l 9, i9., During such movement theribs .Y 33, 3 3,v and Agrooves 34, Mare in meshingy engagemenatepreventrelative movement off-,thc abut:

ting surfaces of the cushioning ,bodiesand'jhe I9, I.9 whereupon the inner members 23, 23, mayvv be moved out of. engagement-with the cushionf ing bodies 29, 29 and be moved counter-clock-f-v wise as,seen in Fig. el to another position a t which the ribs 33, 33 mesh with the grooves;

, 34. 'ihenthe nuts 22 and 38 may be tigl'itened;

on the b oltsgl and 31 to return the outer meme, bers,- l9, I9 toftheir former position, -fIThis acljustment-causes the no-load position of the seat r 2 to 'behigherandthe loaded positiontofre; y main-...the Same- If desredfonventional .limit-.1: y ing meansfsuchas stops maybe used to main-r.- tain-the same n n-load position after adjustment.VA To adjust, the suspension for riders of; 1esser weight the procedure-is Substantially the samer.: VThe putermembers 9-, I9 are spread-apartand the innen-members 23,l 23 movedinaclockwise,V direction asseen in Fig. 1- relative Ato the outer .member and cushioning bodies 29, 29- untilithe grooves.L 34,- 3 4 and ribs 33,V 33ans brought;1 1to` alignment. whereuronthe Quterf,members 19.. la,

are urged toward each otheragain.1 t is ob vious that the same results can be obtained by disengaging the outer members I9, I9 from the cushioning bodies 29, 29 and by moving the inner members 23, 23 and cushioning bodies together relative to the outer members.

Adjustments are provided for diierent size riders in that the seat 24 may be raised or lowered by raising or lowering the post I2 in-the tubular member I I and may be held at any position by tightening the collar I3 with bolt I5. The seat may be moved forward or rearward by loosening the nut 22 on bolt ZI and sliding the outer members I9, I9 forward or rearward between the iianges II, I7 and clamping plates I8, I3 to the desired position where the seat may be secured by tightening the nut 22 on bolt 2I.

In addition to cushioning the seat 24 from vertical forces through shear of the cushioning bodies I9, I9 the cushioning bodies cushion forces from other directions in shear and compression and along with bushing 39 provide a suspension in which the seatl 24 is separated from the bicycle frame I0 by resilient rubberlike material and in which there is no connection of substantially rigid material between the seat 24 and frame I0.

Variations may be made without departing from the scope of the invention as it is dened in the following claims.

I claim:

1. A cycle seat suspension for cushioning relative movement of a supporting cycle structure and a supported seat structure comprising a pair of frustro-conical shaped members in spacedapart coaxial relationship for mounting on one of the structures, a connecting element extending between the members of said pair and mounted thereon for limiting relative spreading movement of the members of said pair, an arm member extending between the members of said pair and around said connecting element for mounting on the other of the structures, and annular bodies of resilient rubber-like material interposed between the arm member and the members of said pair and disposed around said connecting element for cushioning relative turning movement of said arm member and the members of said pair in shear, each of said annular bodies having a greater thickness at the radially outer portion than at the radially inner portion and having grooves extending radially outward and said arm member and the members of said pair having ribs extending radially outward in meshing engagement with said grooves and having apertures adjacent said ribs.

2. A cycle seat suspension for cushioning relative movement of a supporting cycle structure and a supported seat structure comprising a pair of members in spaced-apart relation for mounting on one of said structures, 'a connecting element mounted on said members for limiting spreading movement of the members of said pair, an arm member extending between the members of said pair and around said connecting element for mounting on the other of said structures, a bushing of resilient rubber-like material interposed between said arm member and said aardige connecting element for resiliently limiting relative radial movement thereof, and cushioning bodies of resilient rubber-like material interposed between said arm member yand the memhers of said pair for cushioning relative turning movement of said arm member and the members oi said pair in shear, said cushioning bodies of rubber-like material having grooves extending radially outward and said arm member and the members of said pair having ribs in meshing engagement withsaid grooves in said cushioning bodies and having apertures adjacent said ribs.

3. A cycle seat suspension for cushioning relative movement of a supporting cycle structure and a supported seat structure comprising a pair of frustro-conical shaped members in spacedapart coaxial relationship for mounting on one of the structures, a connecting element extending between the members of said pair and mounted thereon for limiting relative spreading movement of the members of said pair, an arm member extending between the members of said pair and around said connecting element for mounting on the other of the structures, a bushing of resilient rubber-like material interposed between said arm member and said connecting element for resiliently limiting relative radial movement thereof, and cushioning bodies of resilient rubber-like material interposed between said arm member and the members of said pair for cushioning relative turning movement of said arm member and the members of said pair in shear. said cushioning bodies of rubber-like material having grooves extending radially outward and said arm member and the members of said pair having ribs in meshing engagement with said grooves in said cushioning bodies and having apertures adjacent said ribs.

4. A cycle seat suspension for cushioning relative movement of a supporting cycle structure and a supported seat structure comprising a pair of members in spaced-apart relation for mounting on one of said structures, a connecting element mounted 0n said members for limiting spreading movement of the members of said pair, an arm member extending between the members of said pair and around said connecting element for mounting on the other of said structures, a bushing of resilient rubber-like material interposed between said arm member and said connecting element for resiliently limiting relative radial movement thereof, and cushioning bodies of resilient rubber-like material interposed between and attached to s-aid arm member and the members of said pair for cushioning relative turning movement of said arm member and the members of said pair in shear.

ALVIN S. KROTZ.

REFERENCES CITED The following references are of record'in the le of this patent:

UNITED STATES PATENTS Number Name l Date 2,300,379 Faulhaber Oct. 27, 1942 2,476,226 Schwinn July 12, 1949 

